Method of acceleration of gelatinization of cellulose nitrate and liquid nitric esters and the product thereof



Patented Jan.25,1938 2,106,188

* UNITED STATES PATENT OFFICE ZATION OF CELLULOSE NI-TRATE AND LIQUID NITRIC ESTE-RS AND THE PROD- UCT THEREOF ration of Delaware No Drawing. Application January-'6,

Serial No. 705,622

7 Claims.

This invention relates to the acceleration of the gelatinization of cellulose nitric esters and liquid nitric esters, particularly glycerine trinitrate and mixtures of glycerine trinitrate with gelatinized and ungelatinized cellulose nitrate.

The sensitiveness to detonation, the velocity of detonation and the length of time the product may be stored before it becomes unsatisfactory 55 to use, are adversely affected.

Increasing the time of gelatinizatit'm or elevation of the temperature of the reacting materials, while of some benefit, does not overcome the trouble and either prolongation of the time of in the gelatinization of cellulose nitrate with nitroglycerine mixtures. However, we have found, for example, that monoethyl ether of ethylene glycol is more than twice as eflicient as the glycolitself.

its freezing point depressants, such as the glycol mixing or elevation of the temperature intro- 5 nitric esters, polymerized-glycerine nitric esters, duces additional hazards. Acetone, alcoholnitric esters of chlorhydri'ns, etc., and to the ether mixtures and similar solvents of relatively product resulting therefrom. I I low boiling point have been tried but are not The object of our invention is to gelatinize desirable ,because of their volatility; with re- 10 cellulose nitric esters by means of liquid nitric sultant proneness to form explosive gaseous mix- 10 esters with the aid of more efiicient gelatinizatures with air, and toxic poisoning efiect on the tion accelerators than any heretofore known orworkmen. i used; thus making a more satisfactory product ,We have discovered that the alkyl and aryl and obtaining greater speed, economy, and flexi-, ethers of the polyhydric alcohols are exceedingly bility in the production of compositions which inefiicient in the gelatinization of mixtures of 15 valve this process, as for example, smokeless cellulose nitrate and liquid nitric esters, such as powder, blasting gelatins, gelatin dynamitesand glycerine trinitrate. This series of compounds plastics. may be defined by the general formula ROR' In the manufacture of explosives such as in which R. is a polyhydric alcohol residue, or an blasting gelatin, gelatin'dynamites, semi-gelatins, esterified polyhydric alcohol residue, and R is a smokeless powders, etc., which contain cellulose monohydric alcohol residue. In this class of com- 20 nitrate and liquid nitric esters such as nitropounds we mean toinclude the alkyl, aryl, and glycerine, glycol nitrates, dinitrochlorh'ydrin, etc., mixed alkyl-aryl ethers of the polyhydric alcohols it is the usual practice to gelatinize the cellulose as well as alkyl, aryl and mixed alkyl-aryl ethers nitrate by adding it in the fibrous form, to the of esterified polyhydric alcohols. Etherification liquid nitric ester or mixture of two or more may be either complete, or partial, leaving one 25 nitric esters, contained in a mixer provided with or more free hydroxyl groups. The partiallly an agitator. The mixer may or may not be etherified polyhydric alcohol may'have one or provided with means for satisfactorily applying more of itshydroxyl groups replaced by an ester 0 heat. The choice of liquid nitrates, cellulose nigroup, such as chloride, nitrate, acetate, benzoate,

trate and degree of gelatinization have heretofore etc. These ethers of the polyhydric alcohols indetermined Whether or not heat was necessary. clude the alkyl and aryl ethers of the glycols, While nitroglycerine and ethylene glycol dinisuch as ethylene, propylene, trimethylene, and trate are solvents of cellulose nitrates of the butylene glycol; the alkyl and aryl ethers of glycclass used in the manufacture of gelatinized-exerine, erythrite, pentaerythrite, xylite, arabite,

plosives as above described, their solvent action is adonite, dulcite, mannite, sorbite, etc. 35 very slow. To hasten the solution of the cellu- The quantity of the ethers of the polyhydric lose nitrate heat is usually provided. Complete alcohols required to accelerate the gelatinization gelatinization of all the cellulose nitrate fibres of cellulose nitrate with liquid nitric esters is 40 is very difficult to obtain. The fibres tend to exceedingly small. By one method of carrying form aggregates of more or less incompletely out a gelatinization test at 70-80 P. we have gelatinized cellulose nitrate. The surfaces of I found that if 1.5 parts of cellulose nitrate are these aggregates are covered with a film of gelatadded to 100 parts of a low freezing nitroglycerine inized material which prevents the penetration it requires 85 minutes for the mass to attain a 5 of liquid nitric ester to the interior of the aggrecertain degree of plasticity. If, however, 1 part gate-in sufiicient amount to effect complete gelatof monoethyl ether of ethylene glycol is added to inization. Even with excessive periods of-mixa duplicate mixture in a similar test, this same ing it is diflicult to break down all of these degree of plasticity is attained in ten minutes, aggregates. The result is a distribution through- We are aware that U. S. Patent No. 1,640,712

. out the finished explosive of gelatinized, partly issued to Moran claims glycols as accelerators 5o Our improved process of gelatinization may be carried out in difierent ways. We may add the accelerator to the liquid nitrate esters or a mixture of liquid nitrate esters and cellulose nitrate in the mixing bowl; we may choose to mixthe cellulose nitrate and the accelerator to form a solution before admixing the liquid nitrate esters;

or we may elect to mix the accelerator and liquid nitrate and then add the cellulose nitrate. We prefer to stir the mixture during and subsequent to the addition of the cellulose nitrate. We may elevate or reduce the temperature by adding or subtracting heat during the mixing depending on the selection of materials, the degree of gelatinization desired, and the time available for carrying out the process. In the case of ether nitrate esters, such as monoethyl ether of ethylene glycol, we may choose to add the ether to the glycerine or glycol mixture and carry out the esteriflcation of the ether simultaneously with the nitration of the glycerine or glycol mixture.

Among the accelerators of the character described we may specifically mention, as contemplated and satisfactory forms, monomethyl ether of ethylene glycol; monoethyl ether of ethylene glycol acetate; monoethyl ether of ethylene glycol nitrate; hexamethyl sorbite; pentaethyl sorbite; pentamethyl mannite; monomethyl glycerine; diethyl glycerine; trimethyl glycerine; monotolyl glycerine; ditclyl glycerine; methyl glycerine diacetate; dimethyl monochlorhydrin.

Prior, during or after the gelatinization, we may add, for example, in the manufacture of gelatin dynamites, other ingredients, such as oxygen carrying inorganic salts, as ammonium or sodium nitrate; a carbonaceous combustible material,

mono-- an accelerator comprising a pentamethyl mannite.

3. A composition comprising a cellulose nitric ester gelatinized with a liquid nitric ester in the presence of a minor proportion oi. an accelerator comprising an alkyl ether of a hexahydric alcohol, said ether having at least five ether groups.

4. A composition comprising a cellulose nitric ester gelatinized with a liquid nitric ester in the presence of a minor proportion of an accelerator comprising a pentamethyl sorbite. 5. The process of gelatinizing cellulose nitricesters with liquid nitric esters, which comprises bringing about said gelatinization in the presence of an accelerator comprising an alkyl etherof a hexahydric alcohol, said ether having at least five ether groups.

6. A composition comprising cellulose nitric.

ester gelatinized with liquid nitric ester in the presence of an accelerator comprising a pentaethyl sorbite.

'7. A composition comprising cellulose nitric ester gelatinized with liquid nitric ester in the presence of an accelerator comprising a pentamethyl mannite.

JAMES '1'. POWER. KENNETH R. BROWN. 

